Improvement in slide-valves



receipt [esoneri BAiLEY BRAYroNgor Boston, MAssAcnUsn'rrs.-

Leners Patent-No, metadata october 4, 1870;

a IMPRovEMgNT ln SLIDE-VALVES.

The Schedule refenedto xithes Letters Patent' and making, part of the same.

To all 'to whom there presents shall come Be it known that I, GEORGE BAILEY BaAyfroN, of

Boston, in the county of Suffolk and State `of li/[assai chusetts, have .made an invention of novel and useful ,Improvement in Slide-Valves; `and do hereby `declare the followingto b e afull,` clear, and exact` description `thereot',ldue, referencey beingI had to the accompany ing drawing -making partof this speciticatiomand in "whichi Figure 1 is a vertical .and longitudinal.sectionl of a cylinder, steam-chest, and` valve" ofA a steam-engine'. i embodying my i-rnprovementsrj Figure 2 a perspective representation of said valve.

` "This invention relates to means for lessening or removing the friction betweena slide-valve and its seat,

heretofore resulting from the downward pressure of,V steam or other fluids upon 'such valves; or,`in other words, to producerwhatis termed by mechanics a @balanced slide-valveff', i This invention,..consists;in the combination, with a slide-valve, of a plunger,fiittingwithiu a recessor i well, formed in the` upper part of the same, and suspended from a shaft supported`- upon upright sectoral plates "or rocking bearings, which rest upon-the valve seat, 4and serve to uphold` the plungerpiu the manner hereinafter set forth. l, f y

The drawing before alluded'to as accompanying this speciiication, and which illustrates one practical modeV of carrying out the objects of my invention, repre- '1 sentsat Athe'cy'linder, and at `B the steam-chest of a steam-engine, such parts `Vbeing constructed and arranged ln a manner identical with that now generally practiced, with this distinctiononly,that, in some in' stances, the adoption of m'y improvemeutsmight necessitatea slightly-incr`eased height of the' center of such steam-chest. i i

' ,The slide-valve, introduced` in the drawing and ex-` hibited at C, is of the. ordinary nature, so far as `its steamcavity or passage, audits relation to the steanichestand `cylinder-ports, Vare concerned.

In pursuance of `the purposes of my present invent tion, and 1n one practical ,form in which the same may vbe carried out, l erect upon the upper surface of the valve, and monopolizing (with its plunger 4l-iereinaft'er referred to) the greater portion of tl1e steam.-pressure zarea thereof, an upright cylindrical well or inclosnre,

D, the top of the -valve constituting the bottom of such inclosure or well, and Apierced witlrone or more orifices, to permit of` escape of `steamer waterwhich may nd its wayina'dvertently below the auxiliary or compensating portionrof the valve. i

This=.1astmentioued object is represented in the drawing, at E, as a horizontal circular disk or block, or, l what is more desirablefa cup-shaped plunger, of such size as to ll the well D, thisplunger being suspended from 6r making part of a cross-head or rocker-shaft,'G, l surmounting-and spanning the well at right angles to' -thcpath ot'- movement of the valve, an'dconnectcd .with the well by sliding boxes, or their equivalents, which inclose or make part of its opposite ends, such boxes or the ends of the shaft-s being supported in ways or guides c c, created in opposite sides of the wall of the well, and ittingtherein with considerable friction.

'Ihe crosshead or shaft Gmay be dispensed with,

andthe supports ofthe plunger '-be applied at opposite sides ot' the same; but, for obvious reasons of strength and' stiffness or steadiness,-I prefer to retain the cross-head, or its equivalent.

To each outer extremity of the cross-head or shaft y G, I ax orpivot,l asl the case maybe, two upright sectoral plates orrocking bearings, H H,\disposed upon opposite sides ot' and in parallelism with the path ottravel ofthe valve, and resting upon the -Valve-seat I, and serving to support the plunger E within Vthe well D. o i

In practice, itl willfnndoubtedly he found desirable to produce, either upon the valve orvalve-seat, a number of stops, in order to insure the correct rela tionship-of the same and the supports H H, whichv might otherwise, by accidental lifting of the valve proper, be deranged.

f Iii-order to guard against undue passage of steam pr other. tluid'between theplunger and its receptacle,

the encompassing wall or ange e of the latter should be reduced in thickness to such an extent as to permit of its expansion under pressure of steam, and thus seal the joint between the two, ,and present, by this means an impassable barrier tothe passage of steam.

This function of the plunger obviates the necessity of T an artificial packing.

As, by the division of the directsteam-pressure surface of the valve consequent upon the adoption of the plunger, or its equivalent, and the comparatively frictionless mode of supporting the latter, I am'enabled to remove from the valve proper the pressure of steam which drives it upon its seat, less the amount required to maintain it in contact therewith, the only resistance to he'overcome'in operating the valve is that due to the friction upon the supports of the plunger, and between the valve and seat, both-of which are very slight.

. As these results are au economy iu expenditure of i power necessary to drive the valve, iu lessening to a. -great and valuable extent the wear between the valve and seat, with consequent savjpg of steam, and in re, lievingthe valve-eccentrics from wear and strain,` and as the importance and value of such results are well known to persons conversaut with the use of steamengines, and have so often been `comment-ed upon in othel` patents, an elaboration of these points is considered unnecessary in this specification.

That the invention will accomplish the results claimed will be apparent at a glance.

In calculating the proportions of the various parts of a valve constructed as contemplated under my invention for use of locomotive or nou-condensing engines,ldue.regard should be had to the upward pressure of exhaust steam upon the under side of the valve, or the same and the bottom of the plunger, provided a passage for steam through the valve andagainst such bott-0m exists, as hereinbefore mentioned. In those. engines where no appreciable upward pressure ensues from the exhaust, the relative proportions of the parts will be varied somewhat from that last mentioned, being governed bythe degree of upward pressure to which the valve may be subjected.

These points, however, are details ot' construction fort-h. v

GEO. BAILEY BRAYTON.

Witnesses FRED. CURTIS, EDWARD GRIFFITH. 

